Cutter sharpener



Dec. 17, 1940. c. T, GALLOWAY 2.224359 CUTTER SHARPENER Filed June 29, 1958 10 Sheets-Sheet l Q fi I I Zhwemor @Zareyce Tyflowc y attorney Dec. 17, 1940.

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Filed June 29, 1938 10 Sheets-Sheet 4 3nventot @ZCZZ'GfYCQ ZiyzZloukgr Dec. 17, 1940. Q GALLOWAY 2,224,959

CUT TER SHARPENER Filed June 29, 1938 10 Sheets-Sheet 6.

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CUTTER SHARPENER Filed June 29, 1958 10 SheetsSheet 10 I INVENTOR- T aZZowczy \A'TTORNEY E Patented Dec. 17, 1940 PATENT OFFICE CUTTER SHARPENER Clarence T. Galloway, Rochester, N. Y., assignor to Gleason Works, Rochester, N. Y., a corporation of New York Application June 29, 1938, Serial No. 216,553

18 Claims.

The present invention relate'sto machines for sharpening cutter blades and particularly to machines for sharpening the blades of face-mill and disc-typegear cutters. One object of this invention is to provide a machine which will be faster in operation than machines of, previous design for sharpening gear cutters.

A further object of the invention is to provide a cutter sharpening machine which will produce a smoother, finer finish on the sharpened surface and' in which dangerof burning the blades during sharpening is obviated.

Another object of the invention is to provide .a cutter sharpening machine on which the blades of a cutter may be both rough and finish ground.

Still another object of the invention is toprovide a cutter sharpening machine in which the grinding wheel makes a plurality of passes across the face of the cutter blade during the'sharpening of the blade and in which the wheel is fed automatically toward the blade on successive passes so as to take off more stock on each pass.

A further objectof the invention is to provide a machine in which the grinding wheel is withdrawn automatically an extended distance from its normal working path, after all of the blades of a cutter have been sharpened, to permit removal of the cutter fromthe machine, and in which the grinding wheel is dressed automatically. when the wheel is in withdrawn position.

Still another object. of the invention is to provide a dressing mechanism that willso function that the movement of the wheel in its extended path will itself operate .to pass the dressing tool across the wheel and effectthe dressing operation.

A further object of the invention is to. provide means which will prevent dressing of the wheel unless'the wheel is at a predetermined position in its swinging movement.

' Another object of the invention is to provide on a cutter'sharpening machine means'for automatically advancing the grinding wheel relative to the work and to the dressing tool, before each dressing operation, in order to compensate for wheel wear.

The invention also includes various other improvements and refinements having to do with the perfection of machines for automatically sharpening cutters, all of which will appear clearly from the following description and from the recital of the appended claims.

In the drawings:

Fig. 1 is a side elevation of acutter sharpening machine built according to one embodiment of this invention and arranged for sharpening the blades of a face-mill gear cutter;

Fig. 2 is a vertical sectional view of the machine on a somewhat enlarged scale, parts being 5 broken away; g g Y Fig. 3is a fragmentary plan viewof the machine on. an enlarged scale with parts broken w y; Fig.4 is an end elevation looking at one end 10 of the machine, parts being broken away;

Fig. 5 is a fragmentaryview showing, in section, details .of the drive to the crank which oscillates the grinding wheel to pass it backand forth 7 acrossthe blade to be sharpened;

Fig. 6 is a fragmentary sectional view showing further details of the, drive to the mechanically operated parts of the machine; g

Fig. 7 is a view on anenlarged scale and partly in section, showing detailsof the mechanism for producing the alternate movement of the grind- .ing wheel into and out of operative position for the sharpening of each blade of a cutter, and of the mechanismfor effecting full withdrawal of i the grinding'wheel from operative position when all of the blades of a cutter have been sharpened;

Fig. 8 is a view taken at right angles to the view of Fig. 7;

Figs. 9 and 10 are fragmentary views illustrating the operation of the means for insuring that the grinding wheel is at a predetermined position in its arc of swing when it is dressed;

Figs. 11 and 12 are, respectively, layouts of the cams which control the rough-sharpening and finish-sharpening operations;

Fig. 13 is a section on an enlarged scale taken along the line I3|3 of Fig. '1;

Fig. 14 is a sectional view on the line l4-l4' of Fig. 15, showing details of the indexing mechanism of the machine; 1

Fig. 15 is a rear .elevational view of the work head of the machine, showing further details of the indexing mechanism;

Fig. 16 is a fragmentary viewillustrating the positions of the work and of the grinding wheel in the sharpening of theblades of a disc type milling cutter; I

Fig. 17 is a diagrammatic view showing the hydraulically operated control mechanism of the machine;. and

Fig. 18 is an electrical wiring diagram of the 'machine. p

In machines built to operate according to the present invention, the sharpening'operation is 55 effected by grinding back the front face of each blade of a cutter. The grinding wheel used is of the conical type and the sharpening operation is effected by rotating the wheel on its axis and simultaneously swinging it about an axis which intersects the axis of the wheel and is inclined. thereto. In the grinding of any one blade, the rotating wheel is passed back and forth a number of times across the face of the blade. To take off the amount of stock necessary to provide a new, keen cutting edge, the wheel is fed into the blade between passes.

In the machine illustrated in the drawings, the feed is effected by movement of a slide upon which the grinding wheel is mounted and which is movable in the direction of. the axis of swing of the wheel. Preferably the feed movement is controlled by a rotary cam which is constructed so as to impart a continuous feed movement to the wheel during the sharpening of a blade and which operates to return the wheel to original position, after a blade has been sharpened, so that the wheel willbe in correct position to start the sharpening. of anew blade of the cutter,

when the new blade has been indexed into operative position.

In the preferred form of machine, two different feed control cams are provided, one of which controls the feed of the grinding wheel during a rough-sharpening operation and the other of which controls the feed of the grinding wheel during a finish-sharpening operation. Ordinarily, all the blades of the cutter are first rough-sharpened. Then the grinding wheel is dressed and a second light grinding operation is taken on each of the bladesto finish-sharpen it. Manual control means is provided to move the rough and finish feed cams selectively into operative position.

The cutter is held against rotation during the sharpening of. each blade. After a blade has been sharpened, the grinding wheel is withdrawn from operative position and the cutter is indexed to bring a new blade into position to be sharpened. Then the grinding wheel is returned into operative relation with the cutter and the new blade is sharpened. The cutter indexing mechanism may be of any known or suitable type.

When all of the blades .of a cutter have been operated upon, the oscillating movement of the grinding wheel is stopped and the rotating wheel is withdrawn. an extended. distance to permit shifting of the feed cams and/or removal of the cutter and chucking of a new cutter. In the preferred form of machine, the movements of the grinding wheel to and from operative position are controlled by a cam which is mounted upon the same shaft with the cam that controls the operation of the indexing mechanism. The movements of the grinding wheel into and out of operative position are produced by movement of a lever which is fulcrumed intermediate its ends and which is connected at one end to a carriage upon which the grinding wheel is mounted and which carries at its other end a roller that engages in the track of the cam that controls these movements. The fulcrum of this lever is mounted in a slide which can be moved back and forth by a hydraulically actuated piston; When all of the blades of the cutter have been-ground, this slide is moved causing the lever to withdraw the grinding wheel the extended distance away from thework, required to permit taking the cutter off' the machine and chucking of a new cutter thereon.

For dressing the wheel, a diamond or other suitable dressing tool is provided. The dressing tool is held in inoperative position during the sharpening of the cutter, but during the movement of the wheel to its extended withdrawn position, the dressing tool is moved into operative position.

When the wheel is fully withdrawn, the feed cam may be shifted manually and, if the cutter has been completely ground, it may be removed from the machine and a new cutter chucked thereon. The operator can then return the grinding wheel to operative position. As a wheel returns into operative position, the grinding wheel is advanced toward the work to compensate for wheel wear and is then passed over the dressing tool, to be dressed. At the end of the return movement, the dressing tool is withdrawn from operative position.

The movements of the wheel to and from fully-withdrawn position, the movements of the diamond into and out of operative position and the advance of the wheel to compensate for wear are all hydraulically operated and controlled.

To insure correct sharpening, it is necessary to dress the grinding wheel when the wheel is in. the central position of its swing. Otherwise, the diamond will not dress the wheel along a straight line and the wheel will not have a true conical surface. Various safety devices are provided. Among them is means which will move the wheel to its central position, if it does not stop in that position.

Additional safety devices are provided also which insure that the wheel will be out of operative position when it is dressed and which insure that the wheel cannot be moved into operative position while it is being dressed.

Reference will now be had to the drawings for a more detailed description of the invention.

20 denotes the bed or frame of the machine. This bed is formed on its upper face with a plane way or guide 2| and a parallel V-shaped way or guide 22 (Fig. 4). The bed or frame is also formed at one end with parallel plane ways 23 and 24 (Figs. 1 and 2).

Mounted to slide on the ways 2| and 22 is a carriage 25. The grinding wheel W employed for sharpening the cutter is mounted on this carriage 25. Mounted to slide on the ways 23 and 24 is a, slide or carriage 26 on which the cutter is mounted as will hereinafter be more fully described.

The wheel has a conical grinding surface. It is secured in any suitable manner to a spindle 21 that is journaled on anti-friction bearings in a head 28.

The head 28 is fixedly secured in any suitable manner to a sleeve member 30 that is journaled on spaced bearings 3| and 32 (Fig. 2) in a depending circular support or housing 33 which is formed integral with the carriage 25.

Wheel drive 'a belt 314; The pulley 3'! is keyed to a sleeve 38 (Fig. 2) which is journaled on anti-friction bearings in the bed or frame of the machine. This sleeve 38 has a splined telescoping connection with a shaft 39. The shaft 39 is journaled on end a bevel pinion M.

anti-friction bearings in a bracket member 49 and there isa bevel gear 4| keyed to its front end. This bevel gear meshes with a bevel gear 92 which is journaled on anti-friction bearings in the bracket member 40. The gear 42 has a telescoping splined connection with the shaft 43 which is journaled at itsupper end on anti-friction bearings in the head 28. There is a bevel gear 45 keyed or otherwise secured to the shaft 43 and this bevel gear 45 meshes with a bevel gear 46 that is keyed to the grinding wheel spindle 21.

v To sharpen a blade of a cutter, the grinding wheel head 28 is oscillated back and forth about the axis of the shaft 43 to pass the rotating wheel back and forth across the front face of the blade which is being ground. The oscillatory movement of the head 28 is produced by rotation of the crank 59 (Figs. 3 and 5). The crank 50 carries a pin 5| which is adjustable radially by a screw, 53 in a slot 52 which is formed in the crank plate. The pin 5I is journaled in a bushing 55 on which is mounted a ring-member 56 that carries two laterally projecting pins 51. There is an arm or link member 58 connected with the ring member 55 by two connecting members 59. Each of the connecting members 59 is securedin' the link member 58 and has an opening to receive a pin 51. The link member 58 is connected by connecting members 60 and .pins 5| with aring-member 62. This ring-member B2 is integral with a pin 63 which is secured in an arm 65. The arm 65 is integral with the wheel head 28 and projects from one side of the same.

The pins 51 and GI and connecting members 59 and 69 allow of vertical displacement of the head 29 relative to the crank. Thus the oscillating drive to the head is maintained during feed of the wheel which will hereinafter be described.

The grinding wheel oscillates back and forth continuously while it is in operative position. The drive to the crank member 50 is therefore continuous while the grinding wheel is in operative relation with the work. This drive is from the main drive motor Hi (Fig. 6) which is mounted on the bed or-frame of the machine. The armature shaft of the motor'II) is connected by any usual or suitable coupling with a bevel pinion II. This pinion meshes with a gear I2 which is keyed to a vertical shaft I3. The shaft I3 is journaled on anti-friction hearings in the base of the machine and has keyed to its upper The pinion M meshes with a bevel gear I5 that is keyed to a horizontal shaft 16. The shaft I6 is journaled on suitable anti-friction bearings in the base of the machine and has secured to its rear end a spur pinion 11 (Figs. 6 and 4). The pinion TI meshes with a spur gear 79 (Figs. 4 and 5). The spur gear I8 is fastened to a shaft I9 which is journaled on anti-friction bearings in a quadrant 89 that is adjustably secured on the bed or frame of the machine. The shaft I9 has a telescoping splined connection at its inner end with a sleeve 8| which is journaled on suitable anti-friction bearings in a bracket 83 that is secured to the depending portion 33 of the carriage 25. There is a bevel pinion 82 keyed to the sleeve BI. This pinion meshes with a bevel gear 84 which is keyed to the shaft 85. The shaft 85 is journaled on anti-friction bearings in a sleeve or housing 81 which is secured in any suitable manner to the carriage 25. The crank-plate 58 is mounted upon the upper end of the shaft 85.

As already stated. the machine illustrated may be employed for grinding either face-mill type or disc type gear cutters.

Work adjustments The cutter which is to be sharpened is secured in any usual or suitable manner to the work spindle 99 of the machine (Figs. 14 and 15). In Fig. 1, the machine isshown set up to grind the front faces of the blades of a face-mill gear cutter, while in Fig. 16, 'theset up for sharpening the blades of a disc-type cutter is illustrated.

The work spindle is journaled on suitable bearings in a sleeve or housing 9|. An index housing 242 is mounted on the rear end of this sleeve or housing 9|.

To permit of precisely positioning the cutter with reference to the grinding wheel to control the amount of stock to be removed from the blades of the cutter in the sharpening operation, the work spindle 90 is rotatably adjusted on its axis. For this purpose, the rear end of the sleeve or housing 9| is formed with a circular flange 86 (Figs. 14 and 15). This flange has worm wheel teeth 88 cut part-way around its periphery. A worm 89, which is integral with the shaft 96, meshes with'the worm wheel segment 88. The shaft 96, which is manually rotatable, to effect the desired angular adjustment of the cutter, is suitably journaled in the index housing 242 and the index housing 242, as Will appear hereinafter, is in driving connection with the work spindle through the index mechanism of the machine. Therefore, when the shaft 96 is rotated, the work spindle is revolved on its axis'to effect the desired adjustment.

After the described angular adjustment of the work spindle 90 has been effected, the sleeve 9| and index housing 242 are clamped together by the circular gib 99 and clamping bolt I03. The latter is manipulated by the handle or lever I09.

There is a trunnion I I2 (Fig. 1) projecting laterally from each side of the sleeve or housing 9|. These trunnions are journaled in a head II3. One trunnion has an arm II4 fastened to it. This arm carries a Vernier which reads against a scale scribed on one side of the head I I3 in juxtaposition to the Vernier.

The sleeve or housing 9| isadjustable angularly in the head 3 and the scale and Vernier are provided in order to make this adjustment precisely. The adjustment is effected by manual rotation of a shaft I22. The shaft I22 is journaled on the head H3 and carries a Worm (not shown) that meshes with a worm wheel segment (not shown) which is integral with the sleeve or housing 9|. After adjustment, the sleeve 9| is secured in its adjusted position by clamping bolt I23 which is secured to the sleeve 9| and passes through an arcuate slot I24 in the head H3. The bolt is manipulated by a handle or lever I25.

The angular adjustment of the sleeve 9| in the head II 3 permits of inclining the front face of a blade of the cutter with reference to the grinding wheel to determine the front rake angle to be ground on the cutting blades.

The head I|3is mounted for lateral adjustment on a base 92. -This. adjustment is effected by rotation of a shaft 93 (Figs. 1 and 16) to which is secured a pinion 94 that meshes with a rack 95. The rack 95 is secured to the head H3 and the shaft 93 is journaled in the base 92.

The base 92 is ro'tatably adjustable on a post 91, being held on the post by a circular gib 98 which engages under the enlarged head of the post. The post 9! is mounted in the slide 26 for vertical adjustment therein. The adjustment of the post is effected by rotation of av hand wheel I60 (Fig. 13) which is keyed to a shaft IOI that is journaled in the slide 26. The shaft IOI carries a worm I532 which meshes with a worm wheel Hi l that is secured to the shaft I65 which is also journaled in the slide 26. There is. a spur pinion Hi6 keyed to the shaft I05 at the inner end thereof. This spur pinion meshes with the rack I01 that is secured by screws I08 to one side of the post 6?. The post 91 is secured in any position of its vertical adjustment by a clamping bolt H which is mounted in the slide 26 and which passes through a vertical slot formed in one side of the post 97. This clamping bolt is manipulated by a handle or lever III.

The slide 26 (Figs. 1 and 2) is mounted, as already described, on the ways 23 and 24 of the bed of the machine for lateral adjustment thereon. This adjustment is effected by rotation of a shaft II5. This shaft is journaled in the slide 26 and carries at its inner end a spur pinion I I6 that meshes with a rack III which is secured to the bed of the machine. The slide 26 is secured in any position of its lateral adjustment by T-bolts H6 and a gib H9. The T-bolts II8 are mounted in the slide 26 and their heads engage in a T-slot I20 cut. into the end face of the bed. The gib H9 is manipulated by bolts IN.

The rotary adjustment of the base 92 on the post 9? permits of adjusting the work spindle through an angle of 90 or more. This allows of using the same machine to sharpen both facemill and disc-type gear cutters. In Fig. 1, a facemill gear cutter is shown mounted in position to permit the wheel W to sharpen the front faces of its cutting blades. In Fig. 16, the base 92 has been turned on the post 91 through an angle of 90? from the position shown in Fig. 1 and a disctype cutter T is. shown mounted in position for sharpening the front faces of its blades. The lateral adjustment of the head II3 on the base 62, the lateral adjustment of the slide 26 on the bed 26 and the vertical adjustment of the post 91 on the slide 26 are for the purpose of positioning the cutter, which is to be sharpened, in correct operative relation with the grinding wheel, in accordance with the diameter and hand of the cutter. When the various adjustments have been made, a plane tangent to the grinding wheel along the line of contact of the grinding wheel with.- a blade of the cutter will contain the front face of the blade. Then, as the rotating grinding wheel is swung back and forth about the axis of the shaft 43, its line of contact with the blade will move in this plane and grind a plane front face on the blade. The blade is ground back the desired distance by feeding the grinding wheel into the blade as the wheel passes back and forth across the front face of the blade. The feeding mechanism will now be described.

Wheel feed mechanism Keyed to a shaft I30 (Fig. 2) is a double cam member ISI. This cam member is formed with a finishing cam track I32 and a roughing cam track I 33. The cam member I3I is adapted to be held on to the shaft I30 by a cap-member I35 which threads onto the inner end of the shaft I30.

The shaft I30 is journaled on suitable antifriction hearings in a sleeve I31 which is mounted for axial reciprocating movement in a housing I38 that is secured in any suitable manner to the depending portion 33 of the carriage 25. Thesleeve I31 is adjusted axially in the housing I38 to bring the tracks I32 or I33 selectively into engagement with a follower I40. This adjustment is effected by rotation of a shaft I4I which is journaled in the carriage 25' and which carries at its lower enda spur pinion I42. The pinion I4 2 meshes with a rack I44 which is secured to one side of the sleeve I31. The shaft MI is manipulated by the lever or handle I43.

The follower I40 is secured in the lower end of a nut I45 that is mounted in a head I46 and held against rotation in the head by means of keys I I? which slide in elongated slots that are formed in the head. The head I46 is adapted to-slide in the depending portion 33 of the carriage 25 but is held against rotation therein by keys I48 which. slide in slots I49. formed in the depending portion 33 of the carriage. Thehead I46 forms a support for the sleeve member 30 and the sleeve member 30. rests thereon, although thrust washers, such as shown in Fig. 2 may be. interposed between. the bottom end face of the sleeve and the. opposed upper face of the head I46 if desired.

The shaft I30, which. carries the cam member I3I, is driven continuously during a sharpening operation in time with the drive to the crank 50 which oscillates the grinding. wheel. The drive to the shaft I30 is from. the. shaft I6 (Fig. 6) through the. gears TI and. I6 (Figs. 6 and a spur pinion I50 which has a splined connection with the shaft I9 on which the gear I8 is mounted, a spur gear I 52 which meshes with the pinion I50 (Figs. 4 and 5), a spur gear I53 which meshes with. the gear I52 (Fig. 4) and which is secured to a shaft 454,2. bevel pinion (not-shown) which is also secured to the shaft. I54, a bevel gear I55 which meshes therewith and which is secured to a shaft I56, a bevel pinion I5'I which is also secured to the shaft I56 and a bevel gear .I 53 (Figs. 2 and 4) which meshes with the bevelpinion I51. The bevel gear I58 is secured by screws I60 to a cam I62 which, as will hereinafter appear, controls the periodic withdrawals of the grinding wheel from operative position to permit indexing of the cutter. The cam I62 is keyed to a sleeve I64 which is journaled on suitable antifriction bearings in a bracket I65 that is secured to the frame of the machine. The sleeve I64 has a telescopic splined connection with the shaft I30.

Through the means described, it will be seen that the cam member I3I is rotated continuously to impart an alternate rise and fall movement to the sleeve 33 and grinding wheel head 28. The character of this movement will depend, of course, upon the contours of the cam tracks I32 and I33 and which one of these tracks is engaged at any given time with the follower I40. The gearing driving the shaft I30 is so selected that the shaft makes one revolution in the cycle of grinding a blade of the cutter.

Thus, as the rotating wheel swings back and forth in grinding a blade, it is fed toward the blade in order to remove the stock necessary to produce a new, keen cutting edge, and then, when the wheel has been withdrawn from operative engagement with the cutter for indexing the cutter as will hereinafter be more fully described, the wheel is moved back the distance it has previously been fed, so that it will be in initial position ready to commence the grinding of the next blade of the cutter when that blade is indexed into operating position.

' In Figs. 11 and 12, layouts are shown oftypical roughing and finishing feed camtracks. The roughing cam track is shown in Fig. 11. I66 denotes a dwell portion during the time the wheel is withdrawn from the cutter for indexing the cutter. I61 is a rapid feed portion, to feed the wheel rapidly toward a blade at the beginning of the sharpening operation on a blade. I68 denotes the slow continuous feed portion which controls the slow, continuous feed of the wheel into the blade to grind the stock off the blade and I69 denotes the rapid return movement at the end of sharpening of-a blade to withdraw the wheel to initial position, ready to commence the sharpening of a new blade.

In Fig. 12, I66 denotes the dwell portion of the finishing cam track which controls the position of the wheel when the cutter is being indexed. I61is the rapid feed when the wheel has been returned to operative position after the indexing has been completed. I 68' is the portion of the finishing cam path which produces the feed for removal of the stock for finish-sharpening of a bladeof the cutter. I13 is a dwell 1 during which the wheel remains in operative engagement With the blade, simply cleaning up the blade and I69 is the portion of the track producing the rapid withdrawal at the end of the sharpening operation for returning the wheel to initial position.

Mechanism for periodically withdrawing wheel from operative position and returning same thereto be sharpened. Then the wheel is returned into engagement with the cutter; The periodic withdrawal and return movements of the wheel are efiected by operation of the camIBZ through the medium of the lever. I10 (Figs. 4, 7 and 8). This lever is fulcrumed intermediate its ends on a pin I1I that is carriedby a slide I12. At one end, the lever carries a roller I14 which engages in the track way of the cam I-62. At its opposite end the lever is connected by means of a pin I15 with a block I16. The block I16 is adjustable relative to the carriage 25, as will be described'more fully hereinafter, .but is clamped rigidly to the carriage when the machine is in operation. 9 I

The slide I12 is movable in a guide or track I 11 formed in a bracket I18 that is secured by bolts or screws to the bed or frame 20 of the machine. The slide'l12 is held on the guide or track I11 by gibs I19andscrews I8I.'

' Index mechanism When the grinding wheel is withdrawn from operating position, the cutter is indexed. The indexing mechanism may be of any suitable character. That shown in the drawings is of the type described in the United States patent by means of-screws'l85 to the bedor frame of v The leverv I82 carries aroller I86- the machine.

atone end which engages in the track way I81 of;the cam I80. At its opposite end, the lever I82 is pivotally connected to a link I90 which is in turn pivotally'connected .to the piston rod I9I of a pistonI92. This piston reciprocates in a. cylinder I93 which is secured by screws I94 to the bed or frame 20 of the machine (Figs. 4 and 17) 'lhere is a reservoir I95 mounted above the cylinder I93 and in communication therewith. This reservoir is connected to the cylinder I93 on one side of the piston I92 through a duct I96 which is normally closed by a spring pressed ball checkvalve I91. The reservoir is connected with the cylinder I93 on the opposite side of. the piston I92 through a duct I98 which is normally closed by a ball-check valve I99. There are also Icy-passes between the reservoir and the cylinder I93 around each of the ball-check valves I91 and I99. The by-pass, around the ball-check valve I91 is through a duct 200, a spring pressed ball-check valve 201 and a duct 202. The. bypass around the, ball-check valve I99 is through a duct; 204, a spring-pressed ball-check valve 205 anda duct 206. I Thecylinder I93 is connected hydraulically with thecylinder 2I0 (Figs. 14, 15 and. '17). 'At one side of the piston I92, the connection isthrough the duct I98 and a duct 2II. At the opposite side of the piston I92, the connection is through a duct 2I2. There is a piston 2I4 which reciprocates in the cylinder 2I0.

The piston rod 2I5 of this piston is secured'at its upper end to an arm 2I6 which projects from one side of a slide 2I1 that slides on guide-ways formed at one side of the cylinder 2I0. This slide .2I1 is held on these guide-ways by gibs H8 and 2I9. There is a rack 220 secured, by screws 222 to the slide 2I1. This rack meshes with a spur gear segment 223 which is formed integral with a hub member 225. The hub member 225 is rotatably mounted upon a bushing 226 in which the work spindle 90 is journaled.

The hub member 225 is formed at oneside with an arm 228.: There is a pawl 229 pivotally mounted at 230 on this arm. A spring-pressed. plunger 232 which is housed in the arm 228 and which engages the tail of the pawl 229 serves tov urge the pawl 229 into engagement with a notched index plate 233. The index plate 233 is keyed to the work spindle 90 of the machine and is heldv on the Work spindle by a nut 234.

The index plate 233 is locked during grinding to hold the work spindle againstrotation. For this purpose, a locking dog 240 is provided. This locking dog is pivotally mounted at MI in the guard or housing 242 which encloses the index mechanism. The locking dog is constantly 7 urged into locking position by a spring-pressed plunger243 which is housed in the locking dog and which engages with a 1ug 244 that is integral with the index housing 242.

To trip the locking dog out of locking position to permit of indexing of the work spindle, a trip rail 245 is provided. This is secured by screws 246 to the arm 228. This trip-rail is adapted to engage a trip-dog 250 that is pivotally mounted at I on the locking dog 240. .A spring pressed plunger 252, which is housed in the locking'do'g, engages the tail of the trip-dig250 and serves to urge the trip-dog constantly in one direction aboutits pivot 25I. A mg 254 which is formed integral with the lock-dog 240 serves to limit themovement of the'trip-dog 250 in thisQdirection. I,

301 index plate 233, will drop into engagement with Mechanism for withdrawing wheel wholly out of The cylinders 210 and 1:93 and the .ducts connecting them constitute a normally closed bydraulic system so that when the piston I92 is moved Lin-either direction, the piston 214 is moved also. The check valves 19] and I99, 291 and 265 are simply provided to allow excess oil from the system to flow out .of the system into the reservoir I95 and to allow the reservoir to-keep the system full. Figs. 15 and 1'1 show the positions of the parts when the indexing mechanism is in locked up position.

. As the cam 1189 rotates, it will rock the lever.

I82 about its pivot to shift the piston I92 to the right :from the position shown in Figs. 4 and 1'7. This will force the hydraulic motive fluid from the right hand end of the cylinder 193 through the-ducts I98 and 21 I into the bottom of the cylinder 2.19, causing the piston 2 I4 to be moved .upwardly in this cylinder. The motive fluid will at the same time exhaust from upper end of the cylinder 25111 through the duct 212. As the piston 21 4 travelsupwardly, the rack 220 will be moved upwardly with it to rock the hub 225 and arm 228 in a clockwise direction as viewed in Fig. 15. This will cause the trip-rail 245 tocome into engagement with the trip-dog 251] and lift the locking lever 248) out of engagement with the index plate 233. Immediately thereafter, the pawl 229, which has been riding on the periphery of the a notch of the index plate. In the further movement of-the rack 22-0, then, the index plate and the work spindle 99 to which the plate is secured, will 'be rotated to index the work spindle. The indexing movement will continue until the trip dog 25B rides clearof the trip rail 245. Then the locking dog 249 will drop back into engagement with a notch of the index plate. The indexing of the cutter will have been completed. The index mechanism will now be reset. The cam 189 through the medium of the lever 182 will reverse the piston 192 to cause it to move back to the position shown in Figs. 4 and 17. This will cause the piston 214 to be moved downwardly in the cylinder 21!), causing the hub 225 and arm 228 to be rotated in a counter-clockwise direction as viewed in Fig. 15. In this movement of the arm 228, the trip dog 259 will be rocked by the trip rail 245 about 'itspivot 251 against the resistance of the spring'pressed plunger 252 and the locking dog 241] will not be lifted out of locking engagement with the index plate. In this movement of the .arm 228, also, the pawl 229 will ratchet idly over the index plate.

operative position After all of the blades of the cutter have been ground, the grinding wheel carriage 25 is withdrawn completely out of operative position to permit shifting of the shaft I39 (Fig. 2) for shifting the roughing and finishing feed cams I32 and I33 and/or removal of the cutter from the machine and chucking of a new cutter in position.

, The complete-withdrawal movement is efiected automatically and 'is controlled from the automatic stop device provided on the machine. This automatic stop device may be of any usual or suitable construction. Suitable devices are described in the Ford U. S. Patent No. 1,908,626 of May 9, 1933 and, the Hill U. S. Patent No. 1,577,- 1210f March "16, 1926. The stop device which is denoted at 258 in Figs. '1 and 18 is adjusted initially for the number of blades of the cutter that are to be ground in a particular sharpening operation. A cam 259 (Figs. Zand 4) which is keyed toa' rod 251 servesito actuate this vstopdevice. The rod 251 is fastened to the sleeve I-64 to rotate therewith. On each revolution of the sleeve 1.64, that is, each time a blade of the cutter has been ground, the cam 25.9 advances the stop device. When the sharpening operation (rough or finish-sharpening as the case may be) has been eiiected on the last blade of the cutter, the stop device is tripped and the carriage 25 is withdrawn'fully out of operative position. The manner in which this full withdrawal of the carriage 25 is effected and the means for accomplishing the same will now be described.

To effect the complete withdrawal of the carriage 25 out of its normal working path, the slide I12 (Figs. 4, 7, 8 and 1'1) is moved rearwardly. The movement'of the slide 112 shifts the fulcrum 111 of the lever 110, causing the lever to rock about the roller I14 as a fulcrum., Thus an extended movement is imparted to the carriage 25.

The movement of the slide I12 is produced by reciprocation of the piston 260 (Figs. 7 and 17) which reciprocates ina cylinder 253. The piston rod 261 of this piston is secured by a nut 262 to the slide 112.

The movements of the piston 260 are 'con trolled by a valve 265 (Fig. 1'1). This valve slides in a casing 1256 (Figs. 1 and 17) which is fastened to one side of the bed 29 of the machine. The valve is moved manually in one direction by pressing upon the knob 258. It is spring-pressed in the opposite direction by a coil spring 269 which is interposed between the valve and the bottom wall of the casing 266.

There is, of course, a main hydraulic reservoir or sump 211 (Fig. :17) provided .in the bed of the machine. An oil pump which may b-eof any suitable construction .and which is shown diagrammatically at 210 in Fig. 17 is provided to pump the oil from this sump 211 and efiect the hydraulic operations now to be described. The oil pump is driven by a suitable motor denoted diagrammatically at 430 in Fig. 18. A relief valve 212 of standard construction may be provided to control the hydraulic pressure in the supply line from the sump.

The valve 265 is manually depressed to return the carriage to operative position from fullywithdrawn .position. A spring-presseddetent 215 is provided to hold the valve 265 in its depressed position during the ensuing sharpening operations on a cutter. This detent has a beveled inner end and is adapted to engage over the shoulder 216 .of the valve stem. The detent is resiliently held in operative position by a coil spring 218 but is adapted to be withdrawn from engagement with the shoulder 216 automatically on completion of the sharpening operations on a cutter by operation of the solenoid 211.. This solenoid is energized when the automatic stop 258 of themachine .is tripped at the end of the grinding operation as will be described more fully hereinafter. The .detent 215 can be manually operated by grasping .a knob 219..

The valve 295 is shown in Fig. 17 in the position which it occupies when the carriage 25 is in its fully-withdrawn position. The pressure fluid then flows from the pump 210 through the duct 28!), the ports 281 and 282 of the valve 265, and the duct 284 'tothe cylinder 263. The motive fluid is at this time exhausted from the opposite end of this cylinder through the duct 286, the ports 2'81and 288 of the valve 255 and the exhaust duct 290 which leads back to the sump of the machine.

Dressing mechanism At the time of return of the carriage to operative position, the grinding wheel is dressed. The dressing of the Wheel is effected by passage of the wheel over a dressing tool which has been moved up into operative position at the end of the movement of the carriage 25 into inoperative position.

The dressing tool, which is in the form of a diamond 295 (Figs. 1, 2 and 1'7), is secured in a head 296 that is adjustably mounted upon the upper end-of a piston rod 291. Journaled in the head 296 is a shaft (not shown) that carries the pinion 298 which meshes with a rack 299 that is secured to the upper end of the piston rod 291. The adjustment of the head 296 on the piston rod is in the direction of movement of the carriage 25.

The piston rod 291 is secured to a piston 300 which reciprocates in a cylinder I that is fastened in any suitable manner to the bed or frame 20 of the machine.

The movements of the piston 300 are controlled by a-valve 305 (Figs. '1 and 17) which is housed in a valve casing 306 (Figs. 7', 8 and 17) that is secured in any suitable manner to the bracket The valve 305 is operated by movement of the slide I12. There is a lever 308 pivotally mounted intermediate its ends upon a stud 309 that is threaded into the bracket I18. This lever is pivotally connected at its lower end by means of a pin 3I0 with the stem 3 of the valve 305. A pin 3I2, which is secured in a lug 3I3 that in turn is secured to the slide I12, is adapted to engage the free end of the lever 308 to rock this lever in one direction on movement of the slide I12 in one direction. A dog or finger 3I4, which is secured to the slide I12 by screws 3I5, is adapted to engage the free end of the lever 308 to rock the lever in the opposite direction on movement of the slide I12 in the opposite direction. I

When the valve 305 is in the position shown in Fig. 17, the pressure fluid flows fromthe pump 210 through the duct 320, the ports 32I and 322 of the valve 305, the duct 324, the ports 325 and 325 of a shut-off valve 328, the duct 329, the

ports 330 and 33I of a safety valve 334 and the duct 335 to the lower end of the cylinder 30I, moving and holding the diamond 295 in dressing position. At the same time, the motive fluid exhausts from the upper end of the cylinder 30I through the duct 335, the ports 331 and 338 of the valve 328, the duct 340, the ports MI and 342 of the valve 305 and the duct 343 which connects with the main exhaust duct 290.

Safety valves The shut-01f valve 328 is provided to permit withdrawal of the dressing tool from operative position as, for instance, when swinging the work supporting base 92 around from the position shown in Fig. 1 to that shown in Fig. 16'to permit changing over from sharpening face-mill cutters to disc-type cutters. The shut-off valve also acts as a safety valve to maintain the correct relation of the diamond and carriage movements. It prevents return of the carriage 25 to its working position if the diamond is in its lowered, inoperative position. Moreover, when the carriage 2 5 is in operative position, thevalve 328 cannot be moved.

' .There is'a pin or handle 345 secured to the stem 346 of the valve 328 to permit manual movement thereof. The stem 346 of the valve projects beyond the pin or handle 345. If the Valve 265 is in the position shown inFig. 17, the dressin diamond can be moved from operative position by shifting the valve 328 to the left from the position shown in Fig. 17. When thevalve 328 is so shifted, the projecting portion of the stem 346 engages under a cap 341 that is secured to the stem of the valve 265. This prevents downward movement of the valve 265 for returning the carriage 25 to its working position while the diamond is in inoperative position. Further than this, when the valve 265 is down and locked by the detent 215, that is, when the carriage 25 is in operative position, the valve 328 cannot be moved to the left to lower the diamond to inoperative position, because the collar 341 is then in line with the end of the valve stem 346 and prevents movement of the valve 328. Thus, when the grinding wheel is in operative position, the valve 328 cannot be shifted.

The valve 334 is a safety valvewhich insures that the grinding wheel is in its full withdrawn position when dressing occurs. This valve is housedin a valve casing 350 (Figs. 4 and 1'7) which is secured by screws 35I to the reservoir I95. The stem 352 of the valve 334 projects through one end wall of the valve casing and engages with a cam track 355 that is formed on the periphery of the cam I80. The valve 334 is pressed by the coil spring 356 againstthis cam track. In each revolution of the cams I62 and I80, the carriage 25 is moved into and out of operative position, the extent of this movement being determined bythe swing of the lever I10 (Figs. 7 and 8) about its fulcrum I1I. To insure that the grinding wheel will always be dressed in the same way, it is desirable to dress the wheel when it is at one end of this in and out movement of the carriage 25 in its working path. This the valve 334 does. If the machine does not stop with the grinding wheel carriage at the indexing end of its working stroke, then. the valve 334 will be to the right of the position shown in Fig. 17 and the duct 335 that leads to the lower end of the piston 300 cannot be put on supply. Hence, the dressing diamond 295 will not be moved to dressing position.

When the automatic stop device 258 trips at one end of sharpening operations on a cutter, the main-drive motor 10 is stopped. Hence the swinging movement of the grinding wheel and the to and fro movement of the carriage 25 in its limited working path are stopped.

, To insure proper dressing of the grinding wheel, the grinding wheel must be at the center of its swing when it is dressed so that as the wheel-is moved across the dressing diamond, the wheel will move along a generatrix ofits conical active surface and a straight profile wvill be dressed thereon.

To insure that the wheel will be in central position, a combined pusher and lock bar 360 (Figs. 9, 10, 3 and, 17) is provided. This is aflat bar that is secured to the head of a piston rod 36I by a screw or bolt 362. The piston rod 38I is secured to a piston 363 which reciprocates ina cylinder 364 that is mounted on the carriage 25.

When the main drive motor I0 is stopped at the end of the grinding operations on the cutter, it has been found that the crank plate will stop somewhere within 90 of the position at which the grinding Wheel is in the central point of its swing. The pusher. 360 is provided to move the crank .50 on to the desiredpositiomif it does not stop at this position. For .thispurpose, the crank plate is slab-bed off .at oneside as indicated at 356. If the crank plate does not stop in :the desired position, the pusher 388 engages the sla'bbed ofi portion of the crank plate and moves it on from the position in whichit stops such as the position shown in Fig. 9 to the position shown in Fig. 10, which is the correct position of the crank plate for dressing. .If the crank plate stops in the correct position, the pusher 360 simply moves outwardly .to the position shown in Fig. 10 without moving the crank plate; In this position it serves to lock the crank plate against further rotation and the grinding wheel against swinging movement while the wheel is being dressed.

The pusher is actuated at the same. time that the dressing diamond 295 is being moved up into dressing position. The duct 323 which supplies the motive fluid to the lower end of the piston 300 connects with a duct 3'') (Fig. 1'7) which leads to the right hand end .of the cylinder 354. The left hand end of the cylinder 354 is connected by a duct 31I with the duct 335 which leads from the upper end of the piston 333.

Wheel-feed actuating mechanism Before dressing the grinding wheel, it is necessary to advance the grinding wheel toward the plane of grinding in order to compensate for wear of the wheel. For this purpose, a pawl 315 and ratchet wheel 3T6 (Figs. 17, 4 and 2) are provided. The pawl is pivotally connected to a piston rod 378 which is integral with the piston 379 that reciprocates in a cylinder 383 which is secured to one end of the bed 23 of the machine. The piston 3'I3 is constantly urged in one direction by the coil spring 381. It is moved in the opposite direction by fluid pressure. For this purpose, the cylinder 383 is connected by the duct 383, ports 384 and 335 of valve 334 and duct 335 with the duct 233 that leads to the control valve 255.

The ratchet wheel 375 is keyed to a sleeve 333 (Fig. 2) that is journaled in a bearing member 35I that is secured in any suitable manner to the bracket I35. The sleeve 333 has a telescoping connection with the shaft 392. The shaft 332 is held against rotation relative to the sleeve 333 by a key that fits into an elongated groove or slot cut in the shaft 392. The shaft 392 is connected by means of a universal joint with a shaft 394 which in turn is connected by means of a universal joint with a shaft 395. A bevel pinion 333 is keyed to this last named shaft. This pinion meshes with a bevel gear 391 which is keyed to a screw shaft 333 that threads into the nut I45.

The nut M5 is held, as already described, against rotation in the head I45 by the keys I41. The nut I45 cannot move downwardly because it is held against downward movement by the contact of the follower Hit on the track I32 or the track I33 of the cam member I3I. As a result, when the shafts 332, 394, 355 and 338 are rotated, the head I45 is moved relative to the nut I55, thereby raising or lowering the sleeve 30 and with it the head Z38 on which the grinding wheel W is mounted.

Manual adjustment of the position of the grinding wheel for depth of feed may be effected by rotation of the stub-shaft 453 (Figs. 4 and 2) to which is secured the spur gear 40I that meshes with a spur gear 432 which is keyed to the sleeve 390.

The various parts shown in Fig. 17 are illustrated in the positions which they occupy when the carriage 25 is in the fully withdrawn position. To return'the carriage '25 to operative position, the operator depresses the valve 235 by pushing down on the knob 2 58. This causes the duct 286 to be put on supply and the duct 284 to be put on exhaust. The duct 284 exhausts through the ports 232 of the valve 265 and the duct MI]. The duct 4|!) communicates with the main exhaust duct 290. At the same time, the duct 333 that leads to the cylinder 339 is put on supply from the duct 385 through the valve 334. This causes the pawl 3-l5to be moved to the right from the position shown in Figs. 4 and 1'! to advance the ratchet wheel 3'I6and rotate the shaft 398 to ad Vance the grinding. wheel to compensate for the wear of the wheel.

As the piston 25%) moves to the left from the position shown in Fig. 17, the lug 3I4 strikes the lever 308, causing the valve 355 to be shifted from the position shown in Fig. '17 to the position shown in Fig. 7. This causes the upper endof the cylinder 30I to be put on supply from the duct 32!] through the ports 32I and 34I of the valve 305., the duct 340, and the duct 335. The lower end of the cylinder 30I then exhausts through the duct 335, ports 33I and 333 of safety valve 334, duct 323, ports 325 and 325 of shut-off Valve 328, duct 324, ports 322 and M2 of valve 305 and ducts ii-3, 3 33 and 2.90. This withdraws the dressing tool from dressing position. At the same time also that the duct 336 is put on supply and the duct 335 put on exhaust, the duct 3 of the cylinder 334 is put on supply and the duct 31!! of the cylinder is put on exhaust. This causes the piston 363 to be moved to the right in its cylinder 354 to the position shown in Fig. 3.

E ectrical safety devices The grinding wheelcarriage 25 is now in operative position again, the dressing tool is withdrawn from operative position and the crank 50 is unlocked. The normal grinding operations of the machine can now be started by restarting the main drive motor ID. A safety device is provided, however, to insure against starting of this motor until the pusher 363 has been fully withdrawn from operative position. For this purpose, a normally open limit switch 4l5 (Figs. 3 and 1'7) is incorporatedin the starting circuit of the motor 70. A spring-pressed plunger M6 is mounted in a hole inone side of the casting 4II to which the cylinder 354 is secured. This plunger contacts at one end with the roller MB of the limit switch 4I5. The opposite end of the plunger M6 is adapted to ride on the bottom of a cam slot 4I9 which is cut into the head 420 of the piston rod 36 I. In the position shown in Fig. 3, the plunger is riding on the highest point of this cam slot M9 and the limit switch 4I 5 is closed so that the motor I0 can be started. When the piston rod 36I moves to the left of the position shown in Fig. 3, however, the plunger 4H5 rides down to the bottom of the cam slot 4I9, releasing the roller M8 and allowing the switch 450 to open, thus opening the circuit of the motor 10.

An additional safety device is provided to insure against starting of the main drive motor 10 until the carriage 25 has been returned to operative position. This is in the form of a second limit switch 425 (Fig. 3). This limit switch is also a normally open limit switch. It is mounted upon the bed or frame .28 of the machine. There is a cam plate 426 secured to one side of the carriage 25. The roller 421 of the limit switch 425 is intended to ride on this cam plate. When the carriage is inoperative position, the roller 421 is on the-high part of the cam surface and the switch 425 is closed, closing the starting circuit to the motor 10. When the carriage 25 is in fully withdrawn position, however, the roller 421 rolls down on to the low part of the cam plate 426, allowing the switch 425 to open and to break the starting circuit.

Electrical circuit One way in which the machine may be wired electrically in order that it may function properly is illustrated diagrammatically in Fig. 18. The motor which drives the fluid pressure pump is denoted at 439. To start the machine, this motor must be started first. This is-done by pressing in the start button 43! which closes the circuit to the motor 436 from the main lines L1, L2, L3.

After the motor 436 has been'started, the motor 35, which drives the grinding 'wheel, may be started by pressing in the startbutton 435. This closes the circuit from themain line L1 through the start button 43 I, the line 436,-overload switch 431 of a standard controller 438, the overload switch 439 of a standard controller 446, the line 44!, the stop button 442, the line 443, the start button 435, the line 444, the line 445, the solenoid 446, the line 441 and the start button 43! to the main line L2.

The circuit just described energizes the solenoid 1 446 causing the bar 448 to be pulled'to the left from the position shown in Fig. 18 to close the switch arms 449, 459 and 45 I. This closes the circuit from the main lines L1, L2 and L3 to the motor 35 through the main lines'455, 456 and 451 and switches 449, 458 and 45!. The start button 435 is a normally open button'and will fly open when it is released. The circuit to the solenoid 446 is maintained, however, through the switch arm 459 which connects the line 445 with the line 443 through the line 459.

When the pump motor 439 andwheel motor 35 are running and the carriage 25 is in operative position, the main drive motor 19 maybe started by pressing in the starting button'465. "This closes the circuit from the main line L1 through the line 436, overload switches 431 and 439, line 44!, stop button 442, lines 443 and 459, the switch arm 458, line 444,'line 486, limit-switch {4!5 which is at this time closed by cam 419 (Fig. 3), line 451, limit switch 425 which'is at this time closed by cam 426 (Fig. 3), line 468, stop'button '418, start button 465, line 41!, line 412, solenoid 413, line 414, line 415, automatic stop device-258, line 416, line 441, and start button 43! to mainline L2. This energizes the solenoid 413, causing the bar 480 to be pulled to the left from the position shown in Fig. 18 to close the switches 48!, 482, 483, and 485 and open the switch 486. The switch arms 48!, 482 and 483 close the circuits to a the main drive motor 18 through the lines 481,

488 and 489. The start button 465 is a normally open switch, but the circuit to the solenoid 413 is maintained after this button is open, through the switch arm 485 and lines-498 and 49!.

At the same time that the circuit to the solenoid 413 is closed by pressing in the start button 465, a circuit to a solenoid 495 is closed from the line 436 through the lines 496 and 491 to the line 414. Thus the solenoid 495 --is energized to pull the switch bar 498 to the right from the "position shown in Fig. 18 and open the switch arms 499 and 566.

To'move the carriage 25 to operative position, the operator depresses the valve 265 (Fig. 1'1) as already described. This permits the detent 215 to engage over the shoulder 216 of the valve to hold the valve in its lower position as already described. The detent remains in this position while the cutter is being ground. The detent is automatically disengaged when the solenoid 211 (Figs. 17 and 18) is energized. This occurs when the-automatic stop 258 is tripped, after sharpening operations on a cutter have been completed. The switchtarm 502 forming part of the stop is then swung open to break the circuit to the solenoid 413, thus stopping the main drive motor 18. When the automatic stop is tripped, it also breaks the circuit to the solenoid 495, allowing the switch arms 499 and 588 to return to the positionshown in Fig. 18. Thiscloses the circuit to the solenoid 211 from the line 436, through the line 496, the switches 569v and teams 1ine583, the line 594 and the line 441.

As soon as the detent 215 is disengaged, the valve 265 moves upwardlyunder actuation of the spring 269. This causes the slide I12 to be shifted to cause the carriage 25 to be moved to fully disengaged position as above described.

For the convenience of the operator, a light is provided on the machine to indicate to him when the carriage25 is in position to permit dressing of the grinding wheel. 'I'hislight serves, in effect, to indicate thatthe safety valve 334 (Fig. 17) is in open position and that the main drive motor 10 is stopped. The circuit to thislight, which is denoted at 5!!) in Fig. 18, is made through a limit switch 5!! and the switch arm 486. The circuit is from the main line L1 through the line 436, the limit switch 5!!, the line 5I5, the switch arm 486, the line 5!2, the light 5I'8, and the lines 5I3 and 441 back to the main line L2. The limit switch 5!! is operated by a lug 5I4 which is secured to the periphery of the cam I88 (Fig. 4). This cam lug issopositioned that the limit switch is only closed when thecarriage 25 is in its withdrawn position. The switch arm 486 is only closed when the motor '18 is stopped. Hence,'the light 5!!) is vonlylightedwhen the carriage 25'is in withdrawn position and the main drive" motor 10 is stopped. By glancing at the light, then, the

operator can determine the state of the machine.

Adjustments for height of cutter blades to be ground To enable cutter blades of different heights to be ground, the carriage .25 is mounted for adjustment with reference to the lever I16 (Figs. ,7 and 8). This lever, as already described is connected to the block I16 (Fig. 3). This blockis normally secured against movement relative to the carriage 25by apair of bolts 52! and 522. The bolts are connected by the links 524, 525 and toggle member 526 so thatithey can be manipulated simultaneously'by a lever 521 (Figs. 1 and 3). The block I16 is mounted for sliding adjustment in opposed guide-ways 529 that are formed in the carriage 25 andtheiblock is held on these guide-ways by-gibs 536.

The 'block carries a nut 528. Thereis a screw shaft 532 which threads into this nut. This shaft can be rotated by rotating the shaft 583. There is a'bevel; gear 534 keyed to the-latter shaft that'meshes withabevel gear 535-which is keyed to thescrew-shaft. When the bolts 52! and 522 are released, then, the-carriage 25 may be adjusted relative to lever I19 to position the grinding wheel in accordance with the height of the blades of the cutter which is to be sharpened.

At the same-time that the wheel is adjusted, the operator may also adjust the dressing diamond byrotation of the pinion 298 .(Fig. 2). Thus the diamond canbe maintainedin correct operativerelation with the wheel.

General operation of the machine The operation of the machine may now be described. The operator first chucks the cutter which is to be ground upon a work spindle 90 and. makes the necessary. linear and angular adjustments of the work and of the grinding wheel for grinding this cutter. I-Ie also shifts the shaft I30 (Fig. 2) by manipulation of the lever I43 to bring the roughing track I33 of the feed cam into operative engagement with the follower I40. The automatic stop 258 is-also adjusted in accordance with the number of blades in the cutter which is to be sharpened.

When all of the adjustments have been made, the operator starts the hydraulic pump motor I 430 (Fig. 18) by pushing in the start button 43I.

He may then start the wheel drive motor 35 (Figs. 4 and 18) by pushing in the start button 435. This causes the grinding wheel W to be rotated through the pulleys 36 and 31 and belt 38, and the gears 4|, 42, 45, and 46 (Figs. 4 and 2).

The carriage 25 is at this time out of its operating path in full withdrawn position. With the hydraulic and wheel drive motors running, the operator may now move the carriage 25 into operativeposition by depressing the valve 265 (Fig. 17). This causes the duct 286, that leads to the cylinder 253, to be put on supply from the line 280 and the duct 264 leading from this cylinder 263 to be put on exhaust through theline 4! 0. Thus the piston 2651 is moved to the left from the position shown in Fig. 17 and the carriage 25 is carried on into operative position. When the operator depresses the valve 265, the detent 215 engages over the collar 216 of the valve, holding the valve down in its lower positionagainst the resistance of the coil spring 269. At the same time that the duct 286is put on supply, the line 303, which leads to the cylinder 330, is put on supply from the line 286 through the ducts 386 and 363. This causes the pawl 315 to advance the ratchet wheel 316 and through the shafting 392, 394, 395 and the gears 396 and 391 (Fig. 2) to rotate the screw shaft 398. This causes the head I46 and the sleeve 30 which rests thereon and the grinding wheel head 28, which is secured to the sleeve, to be lowered. Thus the grinding wheel support is fed downwardly in a direction, perpendicular to the plane of grinding to compensatefor wear of the wheel.

The diamond 295 is at this time in operative position. Hence, as the carriage 25 moves in to operative position, the grinding wheel W is carried over the diamond and dressed. As the carriage 25 nears the end or its movement inwardly,

the dog 3I4 (Figs. 1'7 and 7) strikes the lever 308 and moves the lever from the position shown in Fig. 17 to that shown in Fig. 7. This shifts the valve 305 from the position shown in Fig. 17 to that shown in Fig. 7. The pressure fluid now flows to the upper end of the dresser cylinder 30I from the line 320 through the ducts 340 and 336. At the same time the motive fluid exhausts from the lowerend of the cylinder 30I through the ducts 335, 329, 324, M3, 343 and 290. Thus, the

diamond 295 is withdrawn from operative position.

At the same time, the pusher 360 (Figs. 17, 9 and 10), whichhas been looking the crank 50 against rotation, is withdrawn from operative position. The pressure fluid flows from the duct 336- to the left hand end of the cylinder 364 through the .duct 3H and the motive fluid exhausts from the right hand end of this cylinder through the duct 310 to the duct 329.

As the pusher piston 363 returns to the right to the position shown in Fig. 3, the plunger 4I6 rides up on the high part of the cam slot 4I9 of the piston rod head 420 and closes the normally open limit switch 4I5. As the carriage 25 moves into operativeposition also, the roller 421 (Fig. 3) of the normally open limit switch 425 also rides up on to the high part of the cam 426 and this limit switch 425 .is also closed.

The operator can now start the main drive motor 10 (Figs. 6 and 18) He does this by pushing in the start button 465. The electrical circult to this motor has already been described. When this motor is started, the crank 50 is driven through the gearing H, 12, 14, 15, 16, 18, 82, and 84 (Figs. 6, and 4). The crank oscillates the grinding wheel head 28 back and forth to swing the grinding wheel to and fro about the axis of the shaft 43 (Fig. 2). At the same time, the motor drives the index cam I80, withdrawal cam I62, feed cam I3I and automatic stop trip cam 259 (Fig. 2), through the gearing 11, 18, I50, I52, I53, I55, I51 and I58 (Figs. 6, 4 and 2).

As these four cams rotate, the cam I62 first causes the carriage 25 to be moved into operative position to engage the rotating and oscillating grinding wheel with a blade of the cutter that is to be sharpened. The cam I62 actuates the carriage 25 by swinging the lever I10 (Figs. 7 and 8) about its fulcrum I 1 I. During this inward movement, the follower I40 (Fig. 2) will be riding upon the dwell portion I66 of the track I33 of the cam I3I- (Fig. 11). W'hen'the rotating and swinging grinding wheel has moved into operative engagement with the cutting blade, however, the follower I40 will move off the dwell of the cam track I33 onto the'porti0ns-I61 and I68 of the camtra'ck, successively, and, as the rotating Wheel swings back and forth across the face of the blade, the wheel will be' fed into the blade by operation of the cam track I33. Thus on successive passes of the grinding wheel across the face of the blade, more and more stock will be ground ofi oftheface of the blade.

When the blade has been sharpened down to the predeterminedextent, the cam I 62 will swing the lever I10 (Figs. 7 and 8) back about the fulcrurn I1 I-to withdraw the grinding wheel out of operative position. When the wheel has cleared the cutter, the ca m I80 will operate to swing the lever I82 (Figs. 2, 4 and 17) about its pivot I83 to shift the piston I92 to the right from the position shown in :Figs. 4 and 17. This will cause the piston 214 tobe moved upwardly in its cylinder 2I0 to cause the arm 228 (Fig. to be moved ina clockwise direction through operation of the rack 220 and segment 223. The locking dog 240 will thus be disengaged from the index plate 233 and thepaw1229 will drop into a notch of this plate and index the work spindle 90 to bring a new blade of the cutter into position to be und-i. I "l .J While; the indexing is taking place, the cam 259 (Fig.;; 12): will be advancing the automatic stop device- 258. 

